Hi hansven,
ILD information isn’t among the specs that many manufacturers would provide or would even need to provide to their customers since ILD has nothing to do with the quality of the materials and your body will tell you much more about whether a mattress is a good match for you in terms of PPP (Posture and alignment, Pressure relief, and Personal preferences) than any “comfort specs” such as ILD.
Unless you are considering Essentia as an actual purchase (and you can read some of my thoughts about Essentia and some of the misleading claims they make and some forum discussions with them in this thread and this thread and posts #3 and #4 here) they probably aren’t worth testing as a reference point because they will be different from most other latex mattresses that you may be considering.
I would make sure you’ve read the mattress shopping tutorial which has all the basic information, steps, and guidelines that you will need to make the best possible choices.
I would avoid trying to design your mattress based on specs or “mattress design theory” that you may not have experience with.
There are really only two ways to decide on a mattress that is a good match for you in terms of PPP (Posture and alignment, Pressure relief, and Personal preferences). The first of these is your own careful and objective testing in the showroom.
If that’s not possible then the alternative would always be to talk with a knowledgeable and experienced online retailer or manufacturer on the phone so they can “talk you through” the options they have available and help you choose which mattress or design has the highest chance of success. In many cases this will be all that’s necessary since they do this every day and have the benefit of years of experience and feedback from hundreds of customers that are similar to you and have purchased their mattresses that they can draw on. Many of them also provide good options after a purchase to either rearrange or exchange layers so that you have good options to do some fine tuning after a purchase if your sleeping experience indicates that it’s necessary. They will know more about their own mattresses and the combinations that are most suitable for different body types, sleeping positions, and preferences than anyone else (see mattress firmness/comfort levels in post #2 here).
Phoenix